Altitude and aspect decide everything after mid March. A resort base above 1,800 m with skiing above 2,500 m on north facing slopes will give you winter mornings into late April; anything lower or sunnier is gambling. That single rule explains this entire ranking, from Val Thorens at the top to why famous mid altitude names are absent.
Ride the clock, not the piste map. Late season snow runs on a daily cycle: firm and fast early, perfect midmorning, heavy by midafternoon on the sunny faces. Plan high and north in the morning, sunny corn around midday, and be on a terrace by three. A week skied this way feels better than a February week fought over powder.
April is also the value window. Lift passes and beds drop sharply after the school holidays, pulling even the Three Valleys toward the $2,000 to $4,000 per person band and Les Menuires below it. Pair this list with our guide to early season skiing in France for the other end of the calendar, and the France guide for the full picture. The high resorts here, led by Val Thorens, reward the gamble most seasons.